Top similar games like Sentry System:

Idol Keeper is a 3D one-player turn based game where you have to make many strategic choices as you face demon waves, with many random events guarantying hours and hours of unique gaming time.

Galactic Garrison is a sci-fi, turn-based tower defense game where you defend your base from relentless alien waves on Mars. Deploy soldiers, build barricades, and upgrade defenses to withstand attacks. Earn powerful reward cards to gain strategic advantages and outmaneuver your enemies.

Tiny Battles is a tactical action auto-battler where battles take place automatically in the arena. Prologue is a demo version of the Tiny Battles game, where 2 of the 5 factions and 3 of the 15 enemy opponents are available to play.

A roguelike auto-battler defense where luck meets strategy. Spin a 3x3 slot machine to summon units and grow your army by absorbing others. Use Items and Cores to manipulate the odds and survive challenging judgement waves and boss waves. Every spin and every choice counts.

Turn your armada into a rotating fortress, striking from every angle. A roguelite tower defense where spatial reads decide survival.

Red Sea is an intense Real-time Tactics game where you control a small team of vigilantes in increasingly challenging battles. It features a Scriptable Tactics system that mixes auto-battling with manual overrides and has a ton of powerful ability interactions to discover.

TD Worlds is a dynamic, highly strategical game that challenges your skill. Build an impenetrable defense and get ready to plunge into a new, unknown world to uncover its secrets. Use Twitch integration and play with your viewers.

Obsolete is a compact real time strategy experience where units act autonomously allowing you to plan and react without micromanagement. Customize your loadout, exploit synergies and establish your own strategy.

Take direct control of your hero on a hostile planet. Build your base, gather resources, expand your territory your way, and survive against the planet’s deadly wildlife.

Tau Cubis is a mazing tower defense game set in colorful sci-fi landscapes. Use your strategic skills to overcome numerous challenges and advance through the leaderboards.

SEND YOUR CREATURES! Build an army of upgradable creatures, hold the increasing amount of lanes and destroy the enemy Portal before you're overrun!

Temporal Titans is a Tower-Defense game with Time Travel. Send mechs back to previous waves to prevent your defeat, and protect your salvage team from the monstrous Grell as you scavenge the ruins of a lost earth. Rewind, rethink, and reclaim the future!

You are the guardian of a cursed labyrinth and must prevent an adventurer from escaping with the help of your monsters. But the adventurer keeps trying again and again, accumulating levels and getting stronger... Survive to the highest possible level !

You wake up in a gloomy room. Become the test subject of a shady software program that feeds on Tower Defense - Roguelike - Deckbuilder simulations.

The hungry Gooper swarm threatens intergalactic peace. Stop them! Build towers around planets and take control over their orbits. Spin them with all you’ve attached! Collect new towers, powers and upgrades to beat the onslaught of goopers and save the galaxy in this colorful Tower Defense Roguelite!

Co-op and Single player Tower Defense genre.

Pirate Rush is an auto-battler strategy game. Choose your crew, strengthen them, dominate the battlefield with your tactics, and clear your homeland of invaders.

Engineer and command the Ironfront Express in a roguelite lane-defense where you build your train car by car with specialized turrets, drones, and tactical abilities, fighting through relentless waves of thousands of corrupted mining machines toward the rogue AI core.

Axon TD lets you expand the map boundaries themselves. A huge arsenal of towers and a wide variety of enemies clash in a battlefield that grows to your whims. Engage in single, cooperative, and roguelite gameplay.

Astro Industry Wars is a lighthearted take on the RTS genre featuring distinct unit types, base building, economic production chains, and customizable unit rosters.

Button Pop is a 3D Tower defense game fused with Button mashing chaos. Construct the deadliest defense strategies by unlocking powerful traps and turrets across a variety of terrains, while building your very own button with the rewards of your adventures!

A minimalist sci-fi tower defense. Buy soldiers and upgrade them, defeat waves of enemies, hold your lines.

Undead army fills the world, and we are trapped in the cave of an ancient god. Roguelike strategic defense! Use your resources wisely, lead your soldiers, and unite the survivors. Ultimately, turn your cave into a fortress capable of defeating the undead king. The fate of the world is in your hands.

A game for those who played hundreds of strategy/roguelikes and want something new and wild. Build your army, explore a harsh random world, fight varied battles, die, start over, experiment, break the game, become godly and destroy everything. Be proud.

Bannerfall is a cute-looking but deeply tactical single-player roguelike RTS. Build custom squads of units, equip them with empowering banners and face sieges, skirmishes and story events as you journey through a randomly generated world each run.

Defend the evacuation of Terra on the losing side of an alien invasion. This experimental action strategy game breaks out of genre norms to provide fresh mechanics to strategic gaming.

Engineered to Purpose is a new tower defence game where you custom-design towers to defend your base, with millions of builds to explore and refine. Set in the far future, E2P's story of posthumanism, family, and change will open new worlds to explore and survive.

Gear up and get going! Defend your outposts from waves of alien enemies with your mech. Build and upgrade your base, protecting the extraction of the mysterious planetary system’s rich resources!

Classic Tower Defense meets space exploration. Build turrets on mining platforms, harvest enemies to build more defenses, and mine Dark Energy to travel the stars. As a sentient AI, you must upgrade your tech, scan planets, and find a new home for humanity before Earth fades away.

Do you like Tower Defense games with Strategy elements? Well, look no further! We've got exactly what you're looking for! Get ready to defend your settlement from enemies using a huge arsenal of towers!

Defend your base against relentless alien waves in a sci-fi tower defense strategy game. Build deadly kill zones, unlock new towers and special abilities, and adapt your loadout to survive escalating assaults across a hostile campaign.

Tower Defense with resource- and base management! Waves of enemy robots with special abilities, shield and armor! Mining, refining and production for building and repairing! Environmental hazards and the best: the Orbital strike!

Cosmic Cult is a roguelike deckbuilder where you're a fledgling god in a dying universe. Assemble the perfect deck of symbols to balance production of metal, faith, and power— or go all in on a single resource. Lead your cult in building a monument to outlast time itself, and make your own luck!

Cosmic Raze is a sci-fi tower defense strategy game. Control advanced weapons, build powerful synergies, and then blast away as aliens attempt to conquer Earth. Between rounds you'll earn unique augmentations, purchase and upgrade a huge variety of weapons, and unlock powerful synergy bonuses.

In Vermin Control, you will enter a thrilling sci-fi tower defense world filled with strategic combat and high tension. Operate a versatile unit capable of both melee combat and construction, deploy and manage 9 unique devices, and protect key facilities from relentless vermin assaults.

TAVU is a PvE RTS game with a tactical combat system. Build your bases and defend them against waves of enemy attacks. Upgrade your units and destroy enemy bases to gain new territories and resources.